Abstract:is one of the most important seawater fish that cultured in China. In recent years, with the breakthrough of grouper artificial seedling rearing, the farming scale of grouper has expanded rapidly, and the gross of cultured grouper reached 59 534 tons in 2011. The effective prevention and control of virus, , and the effective treatment for harmful water quality factors is the key link in grouper artificial seedling rearing. In traditional pond farming mode, strong oxidizers, such as chloride, iodine and potassium permanganate, have played a significant role in disease prevention and water treatment. In recent years, flatfish industrial farming system, as a mature mode, has been driving the technology intergration of grouper recirculating aquiculture system. The solid oxidants mentioned above were greatly limited in the advanced farming mode, while ozone, a kind of gas disinfectant, not only can remove toxic substance such as nitrite, hydrogen sulfide, ammonia nitrogen and killed pathogenic bacteria effectively, but also will not cause secondary pollution, has been widely applied in water treatment of recirculating aquiculture system in the European Union, the United States, Japan and other developed countries. Although the efficiency and stability of ozone disinfection was widely recognized, its security, especially its toxic effects on the cultured livestock, cannot be ignored. In order to evaluate the ozone disinfection and the potential toxicity of ozone to , the efficiency of ozone at two kind of (0.05 mg/L and 0.30 mg/L) on water treatment, such as removing E. coioide as material, the toxic effects of ozone on the embryonic development and post-embryonic larvae were discussed. Our results demonstrated that 0.30 mg/L, the removal rate of nitrite can be up to 72.29% within 3 h; at the applied ozone dose of 0.05 mg/L and a treatment time of 20min, the in the hatching water that was not disinfected by ozone showed a trend of increase, which was fatal to the . However, the higher embryonic development to some extent, which can caused the number of oil globules increased and led to analosis, collapse and death of the embryo, while the hatching rate ), suggesting the lower concentration of ozone(post-embryonic larvae were more sensitive to ozone compared with the post-embryonic larvae died when they exposed to the lower concentration of ozone (0.05 mg/L) for 24 h. The results of this study provided some important reference data and theoretical basis for using the ozone disinfection technology properly in the process of seedling rearing and cultivating of , and was significant to the sustainable and healthy development of grouper rearing.

Abstract:Anodonta woodiana at different juvenile (1.5-month-old, 2.5-month-old and 6-month-old) stages. The results showed that Cyanophyta and Chlorophyta were the major components. The number of dietary algal species in the mussels tended to increase over the juvenile stages (i, e., 11 species at 1.5-month-old, 13 species at 2.5-month-old, and 37 species at 6-month-old). The dominant algal species in 1.5-month-old juveniles were Tetraëdro minimum, while those in 2.5-month-old juveniles were , could be found in < 0.05), reflecting a possibly high The aforementioned results provide important scientific basis to break the dietary algae “bottleneck” for ongoing establishment of the standardized population, and also for the artificial culture and resource enhancement of other freshwater mussels.

Abstract:Parvalbumin (PV) is a major fish allergen that is involved in IgE-mediated food hypersensitivity. Sensitized individuals can develop some clinical symptoms including urticaria, angioedema, asthma, and even fatal anaphylaxis after ingestion of trace quantitiesof fish. As the largest producer and consumer of fresh water fish in the world, a high number of Chinese people suffer from allergies associated with consumption of fresh water fish. Despite this, little is known about the allergens in freshwater fish products that are available in China. We extracted total RNA from silver carp () skeletal muscle, and synthesized first-strand cDNA by reverse transcriptase with an oligo (dT)₁₈ primer. Some specific primers were designed based on the sequences of silver carp PV mRNA (GenBank nos. FJ216937 and FJ216938). Using these primers and the synthesized cDNA, two PV isoform genes (PVI and PVII) were cloned. The full-length of both PVs was 330 bp, which encoded a protein of 109 amino acid residues. The PCR products were cloned into a pMD18-T vector for sequencing. Both the positive plasmid and the plasmid pET28a were digested by H I.The target genes were subcloned into pET28a for expression in [ BL21 (DE3)] by 1 mmol/LIPTG induction at 37 for 4 h. The two target protein bands were ~13 kD, which was consistent with the predicted size. SDS-PAGE analysis indicated that the recombinant PVI and PVII both existed in the soluble fraction of the proteins. The recombinant PVI and PVII were further purified by Ni-NTA agarose affinity chromatography, and the target proteins were eluted by 100 mmol/L imidazol. Both purified proteins yielded a single band on SDS-PAGE. Similar to the native PV, the recombinant proteins reacted strongly with anti-silver carp PV monoclonal antibody in the western blot analysis, suggesting that the recombinant PVI and PVII have strong IgG binding activity. Thus, we obtained two isoforms of purified and biological active recombinant PV. The interaction force of may have a close relationship with the stability and allergenicity of PV. However, there are few reports concerning the relationship between the structure and PV. Therefore, further research will be carried out to determine the relationship between the structure andy of freshwater fish PV and the impact of thermal processing on the stability and allergenicity of different PVs.

Abstract:Tilapia is one of the most extensively cultured species in aquaculture with great economic importance, and has been introduced to nearly 100 countries in the world. China is the biggest country in tilapia production, accounting for about 55% of the total production in the world. In which, Nile tilapia () has played an important role in developing tilapia industry. Since 1978, Nile tilapia first introduced to China, it has been multiply introduced from different countries or areas for several times. Consequently a number of domesticated strains or populations have been established and developed with different selective pressures and divergent genetic characteristics in China. This gives us a chance to combine multiple germplasm resources in breeding practices of tilapia. However, the genetic evaluation and investigation of these domesticated populations of Nile tilapia in China have been relatively poorly conducted. In this study, genetic diversity and genetic relationships of the eight domesticated populations of Nile tilapia in China were examined using partial mitochondrial control region (D-loop) sequence, including the Egypt (EGY), Gilada (GLD), American (USA), Luye (LY), Genomar (GNM), Baolu (BL), Guangdong (GD) and New GIFT (NGF) populations. The results showed that only 15 haplotypes were defined in the 237 analyzed individuals, in which, BL1 haplotype was shared by the five populations (BL, EGY, GLD, GNM, LY), but no one shared haplotype was found for all the populations. The Number of variable sites (), haplotype diversity () and 4 to 83, 0.50 to 37.26, 0.190 8 to 0.802 3 and0.000 8 to 0.056 9, respectively. The genetic diversity in the LY was the lowest in the eight populations analyzed. The results of analysis of molecular variance (AMOVA) indicated significant genetic divergence (<0.01) among the populations. The cluster analysis based on Kimura two-parameter model exhibited the two clusters among them, one cluster included the three populations of BL, GD and NGF, and another cluster consisted of the five populations of EGY, LY, GNM, GLD and USA. However, it was not well supported by the haplotype network profile in network. This study provided insight into the genetic basis of Nile tilapia in combining their germplasm in future

Abstract:is one of the shrimps which have the highest farming production in the world. White Spot Syndrome Virus (WSSV) has been recognized as one of the major threats factors in shrimp aquaculture industry and has been causing severe damage. So the study for antiviral mechanism is extremely meaningful. Ubiquitin proteasome pathway (UPP) is an important cellular functions regulation system in eukaryote. Ubiquitin-conjugating enzyme E2 (UE2) is an integral part of the pathway. According to our preliminary work about transcriptome sequencing and digital gene expression sequencing of gene was expressed significantly higher in hemocyte after WSSV injection. It hints that may take part in the process of virus infection of prawn. But the mechanism is not clear. In this study, the ORF sequence of was amplified by RT-PCR based on transcriptome sequencing. The open reading frame (ORF) was 447 bp, encoding 148 amino acid. The predicted molecular mass of UE2 protein was 16.84 KD, and the theoretical isoelectric point was 4.90.The homology and phylogenetic analysis revealed that the deduced amino acid sequence of exhibited high identity in different species and highest identity wih gene was expressed in all the tissues examined by semi-quantitative RT-PCR. While the expressional profile was detected by real-time quantitative PCR, it showed that the gene was expressed higher in hepatopancreas and intestine than in the other tissues. Then the gene was cloned into the prokaryotic expression vector to yield an identified recombinant plasmid, which was then transformed into competent cells of BL21 (DE3) plysS after being confirmed by sequencing. The recombinant protein approximately 17 kD was gained by inducing expression using IPTG. For antibody preparation, the protein was purified by means of affinity chromatography. These results have laid the foundation for further study of gene and UPP pathway in the process of virus infection of prawn.

Abstract:The DNA methylaiton extent and patterns of CCGG sites in the genome of the Pacific oyster () was investigated among six different tissues using the fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) method. The incidence of DNA methylaiton in the six tissues (gill, adductor, mantle, labial palp, gonad and digestive glands) was 31.77%, 36.41%, 32.00%, 36.47%, 32.77% and 37.92%, respectively. DNA methylation patterns can be divided into two types: the fully methylated and . The fully methylated loci showed similar trend with the total methylation level: digestive glands, labial palp and adductor showed much higher methylation level than the other three tissues and the difference between the six tissues was significant (<0.05). The rate of hemimethylated loci is less than the fully methylated loci and not significantly different between the tissues. Both (bands methylated or unmethylated in only one of the six tissues) and tissue nonspecific differentially methylated regions (bands methylated or unmethylated in more than one of the six tissues) were found in Pacific oyster, but these two kinds of bands only occurred in one or few individuals. No tissue specific/nonspecific differentially methylated regions were found in all individuals analyzed and this might correlate with the high polymorphism in the Pacific oyster. Fluorescence-labeled amplified fragment length polymorphism (F-AFLP) showed the percentage of polymorphism loci was 87.5%, and the expected heterozygosity ranged from 0.267 0 to 0.347 5. Results from F-MSAP and F-AFLP indicated that genetic variation might contribute to the DNA methylation patterns.

Abstract:The Yellow River is the largest river in north China which greatly affects the environment of Bohai Sea. The freshwater input and suspended sediments have sustained the morphology and ecology of the river mouth, located in the northeastern modern Yellow River subaerial delta and was formed after the Yellow River shifted again at the north bank of the Qingshuigou course in June,1996. The water and sediment discharge regulation (WSDR) project has been carried out since 2002 by artificially releasing a large amount of water in a short time, which would affect the invertebrate community somewhat to some extent. In order to know the community structure and its seasonal changes of invertebrate community, the characteristic such as species composition, dominant species, biomass distribution, diversity, and community similarity were studied. Survey were conducted in May, June, early July, late July, August and September, 2012. In the investigated area, 3 sections of 15 sample stations were set up. The distance of the estuary mouth to section A, section B and section C was 10, 20 and 40 km respectively. The 15 stations were radial distributed in the survey area. Data were collected using a beam trawl with a 2.5 m width and a 2 cm net mesh. The trawling speed was ~3 knots and each tow lasted ~30 min. The results showed that a total number of 45 species, which belongs to 9 orders, 29 class and 39 genus, were collected. The number of species was between 28 and 35 in each survey. Diogenes edwardsii, were the main species in Huanghe Estuary. Gastropods (a total biomass of 8.4% to 45.8%) and crabs (10.8%–58.6%) were the dominant category of invertebrate by biomass. The trends of seasonal change of biomass and abundance were most similar. Biomass was highest in August and abundance was highest in early July. The Shannon-Wiener diversity index was between 1.482 (in May) and 1.719 (in June). The results of Bray-Curtis similarity and ANOSIM showed that community was more similarly in the adjacent surveys. But the community in May and June was low similarly with that in August and September. According to the results, we can draw the following conclusions: 1) The community was mainly dominated by small low-valued species. Compared with 1980s, the quality of invertebrate resources was further decline. 2) The seasonal distribution of biomass changed significantly compared with 1980s. 3) The biomass and diversity in section B was more fluctuant and irregular than that in section A and C. 4) Community structure of invertebrate was affected somewhat by WSDR project. But the community replacement was not affect significantly by WSDR. Further research, including the environmental factors and other sample methods, should be utilized.

Abstract:Improving the efficiency of gene transfer and integration is a key objective in transgenic fish research. To evaluate its use for transgenic fish applications, we used the Tgf2 transposon donor plasmid pTgf2-EF1α-eGFP was re-constructed by replacement of the transgenic elements, EF1α-eGFP with the myosin light chain 2 promoter (mylz2) and the red fluorescent protein (RFP) gene, mylz2-RFP. The recombinant transposon donor plasmid, pTgf2-Mylz2-RFP was intended to serve as a transposon donor plasmid that specifically expresses red fluorescent protein in muscle tissue. The donor plasmid and the transposase mRNA were co-injected into zebra fish fertilized eggs. A total of 972 eggs were microinjected and 803 larvae survived, with a positive rate of 76.6%. The red fluorescence () were subsequently cultivated and 10 sexually mature transgenic individuals were mated with wild-type zebrafish, respectively. F₁ individuals that exhibited red fluorescence on their body surface were obtained from one of the mating pairs yielding an integration efficiency of 10%. The positive rate of F₂ individuals, which were generated by mating the mature transgenic F₁ with the wild-type fish, was 69%. The mature RFP positive F₁ individual was then mated with wild-type fish, yielding a 69% positive rate in the F₂ generation. Our results demonstrate that the transposon improves the efficiency of gene transfer and integration during transgene treatments. Thus, the transposon can be used to construct transgenic fish and in other transgenic fish research.

Abstract:). Our objective was to evaluate the epidemiology of the disease and document genotype differences among strains isolated during epidemics at the major giant salamander breeding areas in China between 2010 and 2012. We performed molecular detection, virus isolation and propagation, and viral titer determination. Additionally, the major capsid protein () genes of the virus strains were sequenced and analyzed. The 10 samples that were collected from Shaanxi, Hubei, Hunan, Zhejiang, Jiangxi, and Fujian provinces tested positive. We subsequently obtained 1GSIV epidemic strains genes of the 10 epidemic strains revealed the nucleotide sequences had 99.7–100% similarity and there was little difference among the deduced amino acid sequences. This suggests that all the epidemic strains are of the same genotype. TheGSIVfrogdifferent two branches, but the distanceOur results provide a foundation for the development of a GSIV vaccine.

Abstract:) are widely distributed throughout the Yangtze River, the coastal waters of China and Korea, and the Ariake Sound of Japan. The species is commercially important because of its nutritional value and taste. In recent years, overharvest and changes in the aquatic ecosystem almost resulted in the extinction of the species in the middle reaches of the Yangtze River. Researchers have evaluated a number of measures to conserve the species, including captive breeding in ponds, artificial propagation, and larval rearing. As a result, the immediate threat to C. nasus grow relatively slowly (~125 g in 2⁺ years) so there is a need to improve the growth rate. To determine the molecular mechanisms controlling growth and meat quality in by homologous cloning methods. Its full-length cDNA was 2 252 bp long, with a 1 125 bp open reading frame (ORF) that encoded a 374 amino acid protein. The MSTN protein was predicted to contain a signal peptide sequence, conserved cysteine residues, and RXXR proteolytic sites. Gene expression was deduced by qRT-PCR. The was expressed strongly in the muscle and brain, but weakly in the gills, liver, spleen, intestine, kidney, and head kidney. was not limited to skeletal muscle. Our results suggest that the biological actions of , and possibly in other fishes, may not be limited to skeletal muscle growth repression, but may also influence different cell types and organ systems, particularly brain cells. The gene has shown significant potential in mammalian breeding programs, and our results provide for a basis for development of breeding programs in .

Abstract:and non-ionic ammonia stresses on the apoptosis of cultured in freshwater, changes of cyt-C content and caspase-3 activity were determined by enzyme-linked immunosorbent assay (ELISA) methods after acute temperature variation (16℃←22℃→28℃) and non-ionic ammonia (NH₃), and compared with those of seawater shrimps. It was found that: (1) Thermal stresses significantly increased the cyt-C content in heamolymph and hepatopancreas of both freshwater and seawater shrimps within 5 d (<0.05); three-way ANOVA analysis results showed that culture condition, thermal stress and exposure time all had a significant impact on cyt-C content in shrimps (>0.05). (2) In freshwater shrimps, the caspase-3 activity in heamolymph and hepatopancreas changed significantly after thermal stresses, and increased significantly at 5 d compared to that before experiment (0 d) (<0.05), except the heamolymph after hyperthermal stress, which was different to those in seawater shrimps; culture condition, thermal stress and exposure time all had a significant impact on caspase-3 activity of shrimps and the interaction among them was significant ( concentration of NH₃N, the cyt-C content of heamolymph and hepatopancreas increased significantly in both freshwater and seawater groups ( concentration, cyt-C content in freshwater and seawater shrimps showed a similar change trend: cyt-C content increased significantly within 2N stress and exposure time significantly affected cyt-C content but only cyt-C content in hepatopancreas was significantly affected by culture condition and interaction among them was significant(<0.05). (4) Change trend of caspase-3 activity in heamolymph and hepatopancreas of freshwater and seawater shrimps were similar with those of cyt-C contents, only except hepatopancreas caspase-3 activity kept rising; culture condition, NH₃N stress and exposure time significantly affected caspase-3 activity and caspase-3 activity in heamolymph was significantly affected by their interaction ( in freshwater had a worse adaptive capacity than the ones in seawater under hypothermal stress; the in freshwater showed a similar change of cytthat in seawater in response to NH₃N stress could significantly affect cyt-C content and caspase-3 activity in heamolymph and hepatopancreas of N concentration and avert that water temperature fluctuate dramatically especially in freshwater culture.

Abstract:The salinity will fall depending on the climate in the experimental aquaculture areas of ). And these ares were polluted to a certain extent by some heavy metal such as copper. Therefore, it is necessary to investigate the effect of different CuSO₄ concentrations on silver pomfret in low salinity sea. This study investigated the effects of low salinity on juvenile silver pomfret firstly. We decreased salinity from 24 to 12 by three steps, the salinity change of every step was 4. When fish was in a stable condition, they concentrations was set to in salinity 12, or 0, 0.5 mg in salinity 24. The copper expose was sustained for 144h. Then two kinds of ion-regulatory enzyme activities in gill: Na⁺/K⁺-ATPase (NKA) and V-H⁺-ATPase (VHA) activities, three kinds of antioxidants in liver: glutathione (GSH) contents, superoxide dismutase (SOD) and catalase (CAT) activities of silver pomfret were tested in order to reveal the the effect of water copper on those index of silver pomfret in low salinity sea. In this study, NKA and VHA activities rose then decreased during the salinity decline. After CuSO₄ added into water4 concentration. VHA activities decreased significantly after CuSO₄ added, especially group at salinity 24 increased at 24th hour and then decreased. GSH contents and SOD activity increased significantly through the salinity decline. Meanwhile, CAT activity fluctuated. After CuSO₄ added into water· groups decreased firstly, then increased significantly at 72 h. SOD activities of each CuSO₄ group increased firstly then returned. CAT activities of 0.3 and 0.5 mg increased significantly at 72 h. This study suggested that water copper affected silver pomfret with inhibition of NKA and VHA, especially, in low salinity. The change of GSH, SOD and CAT can reflect the damage of low salinity and CuSO₄ on silver pomfret. The resistibility of silver pomfret to water copper is between a certain range, but we should pay attention to the concentrations of heavy metal such as copper in water when the water environment has changed, for example, salinity had fallen.

Abstract:We investigated the influence of salinity at different levels (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) and alkalinity (0 mmol/L, 10.00 mmol/L, 15.85 mmol/L, 25.12 mmol/L, 39.81 mmol/L, 63.10 mmol/L) on the sperm motility and fertilization rate of Songpu mirror carp ( in this study. The results showed that: 1) The drastic movement time, rapid movement time and life span of the sperm of gibel carp and were the longest when the salinity was 4, and the duration of gibel carp sperm were (90.11±9.03) s, (126.34±13.90) s and (154.27±11.36) s, respectively; while the duration of sperm in were (48.91±1.43) s, (62.19±4.28) s and (90.68±4.46) s, respectively. The drastic movement time, rapid movement time and life span of the Songpu mirror carp sperm were the longest at the salinity of 5, and they were (72.44±9.42) s, (102.16±8.82) s and (206.99±6.65) s, respectively. 2) When the salinity was higher than 8, the initiation of these sperm of the three species were all inhibited. When the salinity was higher than 10, the sperm of gibel carp and were dead, and when the salinity was greater than 11, the sperm of Songpu mirror carp was dead. 3) For alkalinity, at alkalinity of 15.83 mmol/L, the drastic movement time, rapid movement time and life span of the three fishes were the longest, and the sperm motility were significantly greater than other alkalinity groups (4) The fertilization rate of gibel carp and were the highest at salinity of 1, and they were 63.0% and 68.0%, respectively. The fertilization rate of Songpu mirror carp was 72.3% at salinity of 3, which was the highest among all salinities. At alkalinity of 10.00 mmol/L, the fertilization rate of the three fishes reached the highest, which were 75.4%, 54.0% and 66.0%, respectively. Consequently, the effects of salinity and alkalinity on the sperm motility and fertilization rate of the three fishes were obtained in present study, which may provide basic data for the exploitation and development of fisheries in carbonated saline waters in North China.

Abstract:Vaccination is an effective method for controlling bacterial and diseases of fish. At present, researchers have paid more attention to variations of immune related genes expression to evaluate the immune effect of vaccine, besides the changes of antibody level of serum and mucus, enzyme activity, number of lymphocytes, respiratory burst, complement activity and so on. The proinflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor α (TNF α) and chemokines are the key factors in inducing inflammatory and immune cell migration, immune regulation and stimulating the proliferation of T cells and B cells. Major histocompatibility complex class I (MHC I), major histocompatibility complex class II (MHC II), T cell surface receptor CD4, T cell surface receptor CD8 and immunoglobulin M (IgM) play key roles in different stages such as presentation and recognition of antigens and immune response after pathogens invasion. These factors finally to remove pathogens and maintain healthy through a series of immune response. Numerous studies have showed that the vaccine could cause rapid changes in many immune related genes. For purpose of studying the influence of immune methods of vaccine on expression of immune related genes, were injected intraperitoneal and immersed with inactivated vaccine respectively in this study. The expression of seven immune related genes, IL-1β, TNF α, MHC I, MHC II, CD4, CD8 and IgM in spleen, head kidney and gills was determined by quantitative real-time polymerase chain reaction (qRT-PCR) at 0 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h, 96 h, 7 d and 14 d post immunization. The results showed that, the expression of all the tested genes varied significantly. In the injection group, the expression of IL-1 β and TNF α reached the peak between 12–24 h, and MHC I, MHC II, CD4 and CD8 occurred between 48–72 h and peak of IgM appeared at 7 d. The gene maximum expression was 2–70 times higher than that of control group. By contrast, in immersion group, the expression of IL-1 β and TNF α reached their peak between 12–48 h, and MHC I, MHC II, CD4 and CD8 occurred within 48–96 h. IgM peak appeared at 96 h in the gills, but 14 d later in spleen and head kidney, the maximum amount was 2–20 times higher than that in control. The results indicated that, the transcriptional level of genes in injection group was higher than that of immersion group in spleen and head kidney. In addition, the highest value appeared earlier in injection group than in immersion group. However, the gene expression peak in gills appeared later than immersion group. Data are referring for the evaluation of vaccine.

Abstract:The present study was conducted to investigate the effect of yeast β-glucan (Angel Yeast Co., Ltd, Yichang, China) either by orally (in feed) and injection or β-glucan and emulsion-oil vaccine (β-AH) on the immune response and its protection against an infection of the bacterial pathogen carpio haematopterus. And 1 800 healthy with body weight of (32.33±0.21) g were selected, and randomly divided into 12 And groups (Ⅰwith 3 replicates in each group and 50 fish in each replicate. Five levels (150, 300, 450, 600 and 750 mg/kg) of β-glucan were added in the diets of ⅡⅫ groups were fed with basal diet (0 mg/kg β-glucan), respectively. On the first day (00: 00) before the experiment, three different dosages of β-glucan of 150, 450, 750 mg/kg(body weight) of fish were injected intraperitoneally to the of ⅦⅫ groups. Similar, yeast β-glucan was administrated by injection with inactive vaccine and oil emulsion for Ⅹ, Ⅺ and Ⅻ groups in three doses (1.50 g/L, 4.50 g/L7.50 g/L) respectively. On the 7 th, 14 th, 28 th, 35 th, and 42 th days of the experiment, LZM, PI and agglutinating antibody titer were determined. On days 43 and 50 the fish were selected and divided into two subgroups under each treatment group for challenge with 2×LD₅₀ concentration of and subsequently, RPS was recordedon day14 post challenge. The results showed that LZM and PI rose to their highest levels on day 35, and the highest protectionin the challenge study after feeding with the diet containing 450 mg (yeast β-glucan)(diet), however, there was no significant difference in agglutinating antibody titre of . On the contrary, the result was observed depressed those parameters in ( injected β-glucan and β-AH significant enhanced the LZM, PI, agglutinating antibody titre and RPS than control and test fish fed with diets supplemented β-glucan. The results indicated that those parameters rose to their highest levels on 35 days at a medium dose. Injection of high-dose β-glucan and β- LZM, PI, agglutinating antibody titre and RPS in 42 d gradually strengthen contrast medium. The challenge by 2×LD₅₀ result showed that the RPS was significantly increased with increasing dietary β-glucan up to 450 mg/kg (85.46±7.71, < 0.05), but there were no significant differences for β-glucan 450 mg/kg to 600 mg/kg (> 0.05), and decreased thereafter with further increases in dietary β-glucan. Compared to the dietary supplementation, does injected with β-glucan and β- had increased RPS. The best RPS of fish was obtained at 450 mg/kg or 4.50 g/L respectively. It could be concluded that the yeast β-glucan can be used as immunostimulants and enhancement of immunity and survival of the

Abstract:, a gram-negative bacterium has been described to be among the most common and economically important aquatic pathogen of fish and shellfish. Vaccine immunization is an effective approach to prevent infection. And attenuated vaccine could stimulate systemic immune response in host administrated. Now there has been little attenuated vaccine of . The type III secretion system (T3SS) is used by bacterial pathogens to inject effector proteins into the cytoplasm of their host cells. And it is an important pathogenic factor of . The T3SS consists of a structure called needle complex, which is made of a multi-ring base that spans the bacterial and a needle-like extension that protrudes several nanometers from the bacterial surface. is located at the “needle” site of T3SS. Its role is to escort the molecular chaperone and effector proteins into host cells, and further induced host cell death. In this paper, combining with chloramphenicol (Cm) and sucrose screening, an in-frame deletion mutant of using overlap PCR and homologous recombination technology was constructed. And the LD₅₀ changes of ZJ03ΔvscO mutant strains compared with the strain ZJ03 were examed. Grouper (), body length (17±3) cm, body weight (50±5) g were injected with ZJ03ΔvscO and ZJ03, respectively. The ΔvscOmutant showed about 150 times decrease in virulence in grouper. The ZJ03ΔvscOwas used to immunize grouper by way of injection and immersion. The result indicated that the specific antibody titers were markedly higher than that in the control group (<0.05).The relative percentage survival (RPS) of injection group was 84%, while the RPS of immersion group was 68%. The results showed that the ZJ03ΔvscO of has a high immunogenicity, and can be a live attenuated vaccine. In addition, . The purpose of this study is to provide technical support for fish diseases caused by

Abstract:Integrated fish farming is commonly practiced in Guangdong Province in South China. Animal manure generated from livestock and poultry (commonly pigs and ducks) is directly excreted into, or transported via pipes, to fish ponds where the nutrients support the growth of photosynthetic organisms. The use of a wide variety of antimicrobials in livestock and poultry has led to antimicrobial-resistant bacteria. Thus, there is concern over the potential for transfer of these bacteria into the integrated culture systems. Our objective was to determine the antimicrobial susceptibility and homology of were isolated from pig/duck waste, fish, pond water, and sediments from four integrated fish farms in Guangdong Province. We used the Kirby-Bauer disk diffusion method to determine the susceptibilities to 8 classes of 24 antimicrobials. The genomic DNA of the isolates was extracted and the molecular typing was analyzed by entero bacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) and pulsed field gel electrophoresis (PFGE).The resistance frequencies of ampicillin, amoxicillin/clavulanate, and rifampicin were relatively high in the 57 isolates, and the resistance profiles varied among the different isolates. The isolates were grouped into 24 clusters by ERIC-PCR and 46 clusters by PFGE. Isolates from different sources within the same integrated fish farm exhibited similar or identical genotyping patterns between the two molecular typing methods, and they were also associated with similar resistance patterns suggesting they were homologous. Our results suggest that ERIC-PCR and PFGE have use for analysis of clonal relationships and tracing of the source of resistance in Integrated fish farming systems appear to be susceptible to the transfer of drug-resistant bacterial strains from livestock and poultry to fish or the environment. The impact of antimicrobial resistance in the fish was not addressed in this study and remains to be determined.

Abstract:Risk analysis has been used regularly in the management of aquatic animal health, resulting in increased success at preventing and controlling diseases. A number of factors affect the efficacy of a vaccine in aquaculture. Thus, it is important to identify these risk factors and estimate their weights. We developed a quantitative risk assessment model for the prevention for grass carp hemorrhage disease by analyzing epidemiological study data using the Delphi method and meta-analysis. The model was composed of a risk hierarchy system, weight and valuation standards for each risk factor, and an integrated evaluation function. The risk hierarchy system included 5 criterion layers and 24 index layers. The criterion layers included vaccine quality (B1), immune program (B2), fish (B3), pond environment (B4), and care and management (B5) with a set of weight about ={0.267, 0.102, 0.131, 0.263, 0.237}. The index layer consisted of vaccine species(C1), storage temperature and expiration date(C2), storage and transportation conditions (C3), storage of the vaccine (C4), health status of the fry following vaccination(C5), vaccination technique(C6), vaccination dosage(C7), number of unimmunized fry (C8), source of fry (C9), health status of fish(C10), size of fish(C11), water temperature(C12), dissolved oxygen(C13), ammonia nitrogen(C14), nitrite(C15), pH (C16), water transparency(C17), water color(C18), thickness of mud(C19), rearing density(C20), culture type(C21), drug use(C22), feed(C23), and grass feed(C24) with a set of absolute weights about ={0.138, 0.059, 0.046, 0.024, 0.035, 0.018, 0.027, 0.022, 0.040, 0.054, 0.037, 0.076, 0.037, 0.032, 0.030, 0.027, 0.018, 0.019, 0.024, 0.104, 0.024, 0.027, 0.062, 0.020}. The results of the risk assessment were represented by the integrated evaluation function. Using vaccination data from southwest China to validate the model, the integrated evaluation value from three infected ponds was 0.572, 0.638, and 0.617. These values were significantly higher than values from non-infected ponds (<0.01).The results of the risk assessment are consistent with the survey data. Thus, our model can be used to reduce the risk of grass carp hemorrhagic disease by allowing culturists to plan with more certainty for increased immune efficacy.

Abstract:, growth, and survival of juvenile sea cucumber during a 30 d feeding trial. Animals were fed one of four diets in which 0, 10%, 15% or 20% of the carbon source was replaced with sucrose. Additionally, we tested the effect of water-exchange frequency (3 or 7 d). The experiment was set up using an orthogonal design and we measured growth performance, survival, enzyme activities, and soluble protein content. The activities of amylase(AMS) in the experimental groups were generally higher than in the control, indicating that the bioflocs stimulate amylase activity in . On day 15, superoxide dismutase(SOD, 32.9 U/mg prot)and alkaline phosphatase (AKP, 146.8 U/g prot)activity was higher in the 3 d/15% group than in the other three groups and the control( Similarly, SOD (35.3U/mg prot) and AKP(158.8 U/g prot) activity was higher in the7 d/20% group than in the other three groups and the control group( AMS and SOD activity were higher on day 30 than on day 15 in the 7 d/10% group and the increase in AKP activity was particularly significant. The growth rate (4.12%/d) and survival (98.9%) were highest in this group, whereas survival was lowest (91.8%) in the 3 d/20% group. Furthermore, the soluble protein content in the body wall of was not different from the other three groups and the control ( was higher in the 7 d/ 15% group than in the control(<0.05), but was not different from the 7 d/10% group. Thus, our results suggest that areduction inwater exchanging frequency and feeding quantity may be beneficial to growth performance and soluble protein accumulation in . Our results provide a basis for feeding quantity and water-exchanging frequency for juvenile sea cucumber in biofloc technology systems.

Abstract:A number of fish populations have been subject to severe fishing pressure throughout the world as demand for marine fishery products has increased. As a result, the abundance of many traditional commercial fish species has declined significantly. Climate change, overfishing, pollution, and other human activities are thought to be the primary reasons for habitat changes in certain regions, and have also played a key role in the degradation of fisheries resources. Thus, an understanding of the relationships between environmental factors and fishery communities is critical for the conservation and sustainable exploitation of fishery resources. We evaluated the species composition and diversity of the fish community in Jiaozhou Bay and adjacent waters using data from seasonal bottom trawl surveys collected in February, May, August, and November 2011. We used the index of relative importance (IRI), species diversity indices, and multivariate methods to determine the fish community structure over time, and the relationship between fish community structure and environmental variables. A total of 57 fish species were captured, belonging to 2 classes, 10 orders, 31 families, and 46 genera. Most of these were warm water species. The dominant fish species were etc..The Margalef species richness index ranged between 1.36 and 1.73, and the Pielou evenness indexranged from 0.61 to 0.76. The species richness index, but not the Shannon diversity index and Pielou evenness index, changed significantly among seasons (ANOVA). ANOSIM analysis also indicated that the fish species composition in Jiaozhou Bay and adjacent waters varied significantly among seasons. The SIMPER analysis revealed that were the primary discriminating species in the fish community between seasons. The CCA suggested that water temperature, salinity and pH, followed by sediment type, had the most influence on the fish community assemblage. The species diversity indices of the fish community exhibited a stable seasonal pattern, which was consistent with the historical studies. The preference of fish species for different water temperatures may explain the seasonal variation in fish community structure in Jiaozhou Bay.The abundance of goby fish in areas with clay sediment was attributed to the presence of polychaetes, cumacea, and other benthic organisms which provided a food supply. Fish community structure was affected by the combined effects of a range of environmental factors. Further studies are needed to provide management suggestions for fishery conservation and sustainable resource exploitation.

Abstract:Sthenoteuthis oualaniensis in the open waters of South China Sea, two acoustical surveys were conducted using scientific echosounder (Simrad EY60) in the area of central and southern South China Sea (16°–5°N) in the autumn in 2012 and the spring in 2013. The survey results showed: (1) in the autumn in 2012 were 3.26×10¹⁰ inds and 2.14×10⁶ t respectively and the coefficient of variation was 23%; the mangle length range, mean mantle length and mean body mass of were 62, 127 mm and 65 g, respectively; in the autumn population distributed in the entire central and southern South China Sea, mainly distributed north of 8.0°N and 114.0°E area; the maximum abundance density and biomass density of (6.5°N, 111.0°–111.1°E) and 85 t·nmi^–2 (15.0°N, 114.35°S. oualaniensis in the spring in 2013 were 2.98×10¹⁰ inds and 2.44×10⁶ t respectively and coefficient of variation was 23%; the mangle length range, mean mantle length and mean body mass of Sthenoteuthis oualaniensis were 73, 122 mm and 82 g respectively; in the spring population also distributed in the entire central and southern South China Sea, mainly distributed north of 11.0°N area; the maximum abundance density and biomass density of (13.0°N, 116.55°115.35°E) respectively. The research results indicated that the biomass of t in the open water of South China Sea; compared with the autumn in 2012, concentrated ground of moved north and east in the spring in 2013.

Abstract:We developed an “Integrated Habitat Index (IHI)” model based on the quantile regression method using survey data collected at 43 sites in waters near the Cook Islands from September, 2012 through November, 2012. The model variables included vertical profile data for temperature, salinity, chlorophyll-, horizontal current, vertical current and catch per unit effort (CPUE) of albacore tuna(), and the interactions among these variables. Models were developed for five 40 m water strata between 40 m and 240 m and the entire water column to predict the spatial distribution of albacore tuna. The environmental variables measured at modeling sites were used as inputs to the IHI models to predict the IHI value of the 5 strata and the entire water column. We tested for a significant difference between the observed CPUE and predicted CPUE within the 5 water strata and the entire water column using a Wilcoxon test. The Spearman correlation coefficients were assumed to indicate the predictive power of the IHI model. The trend line of the arithmetic average about the predicted IHI for the 5 strata was compared with the CPUEs at the specific depth stratum. The environmental variables at validation sites were used to validate the model’s predictive power. These data were input into the CPUE models to predict the CPUE of the 5 water strata and the entire water column. We used a Wilcoxon test to compare between the predicted and observed CPUEs within the 5 water strata and the entire water column to validate the IHI results. The CPUE for albacore tuna in the 5 strata and the entire water column exhibited a skewed normal distribution with a longer left tail. There was no significant difference between the nominal CPUEs and predictive CPUEs of albacore in the 5 water strata and the entire water column at the modelling sites or the validation sites. The IHI models had good predictive power, and were able to accurately predict the distribution of albacore tuna in the 40 strata and in the entire water column. The key environmental parameters in the IHI models differed among the depth strata. In the shallow water (40), there was a close relationship between the CPUE and water color. Conversely, water temperature, sea currents, and bait and water temperature were the most significant variables in the 80, and generally between 160 and 200 m. The CPUE was 20.31 ind/(1000 hooks) in this water strata. The IHIs for albacore tuna in the area between 13°S167°W were relatively high. When fishing in these areas, our results suggest that fishing gear should be deployed at a depth of 160

Abstract:nd therefore more common to be included in the stock assessment and fishery management as a relative index of abundance. However, scientists have found strong evidences that the proportional relationship between CPUE and abundance is difficult to be upheld under negative influences exerted by a lot of factors. There have been various methods developed to standardize CPUE to reducing the influence of these factors on CPUE and to rebuild the proportional relationship. Due to the importance of CPUE as the primary source of abundance information for many of the world’s fished species, standardization of CPUE remains a very important foundational work for the stock assessment and fishery management for many fisheries. In this paper, we introduced the basic idea and process of standardizing CPUE and then reviewed statistical models for standardization of CPUE and corresponding methods of model selection. We stressed on the uncertainty of model selection and introduced a method of model averaging for multimodel inference. Meanwhile, the present paper discussed the problems with the standardization of CPUE and presented prospects of their future development.